Background: Recent human immunodeficiency virus (HIV) and hepatitis C virus (HCV) outbreaks, including the one in Indiana, illustrate that these infections should be addressed simultaneously to improve outcomes. In the United States most of the new HCV infections are among young people who inject drugs (PWID). Studies at detoxification centers have shown that linkage to care is problematic. Social services support such as case management has the potential to improve linkage to care; however, little is known about its potential influence on the care of young PWID. Candidate: I am a clinician scientist trained in combined internal medicine/pediatrics and infectious diseases (ID). I am committed to investigating strategies to improve health care delivery to HCV- and HIV-infected individuals. After completing an ID fellowship at Harvard's Beth Israel Deaconess Medical Center, I joined the faculty at Boston University (BU) School of Medicine, where I have gained experience working with substance using patients. I am applying for a 5-year K23 award to acquire the necessary skills and experience to become an independently funded clinician investigator with expertise to design, implement and analyze clinical interventions. Research: I will use the ADAPT-ITT framework to modify strengths-based case management (SBCM), an evidence-based linkage to care intervention, to address the needs of PWID aged 18 to 30 tested for HCV and HIV at a detoxification center. I will then pilot test the adapted intervention. The specific aims are to (1) To use in-depth, qualitative interviews to identify facilitators and barriers to linkage and retention in HIV and/or HCV care; (2) To use findings from Aim 1 to adapt SBCM to improve linkage and retention in care; 3) To conduct a feasibility study of the adapted intervention in preparation for a future trial. Training: The career development plan includes training in the development of interventions, clinical trials, advanced statistical methods, and substance use research. The BU ID department, the Centers for AIDS Research (CFAR) and the NIH-funded Learning for Early Careers in Addiction and Diversity program provide a rich research environment. Mentorship: My primary mentor, Dr. Samet, has expertise in substance use, HIV and HCV. Dr. Linas, my co-mentor, has expertise in HCV, HIV and linkage to care. Advisors are Drs. Bernstein (qualitative research), Horsburgh (HCV and HIV) and Sorensen (substance use and HIV). At the completion of my K23, I will have gained the skills necessary to become an independent clinician investigator focusing on HCV and HIV linkage to care among individuals with a history of substance use.